The invention relates to a device for the axial and radial setting of a forme cylinder for register printing, particularly on multicolor printing machines.
The present invention provides a device for continuous and precise axial and radial setting of a forme cylinder of a printing machine to obtain register printing which can be used during the printing operation of a printing machine whereby it is possible to take up the clearance of gears in the setting mechanism. The control elements can be arranged on one side of the printing machine to provide easy control of the mechanism.
One of the known devices for the axial and radial setting of a forme cylinder for register printing consists of a pair of helical gears, one of which is rigidly connected with the forme cylinder, the second helical gear being mounted coaxially on the shaft of the forme cylinder. These gears engage a pair of connected pinions which are arranged on a shiftable countershaft, the end of which is provided with a screw which is screwed in a nut which is fixed to the side wall of the printing machine. The nut is directly or by means of an element connected with a control knob.
A disadvantage of this device is that it is necessary to use four gears for the setting of the forme cylinder, the accuracy and vibration of which have a negative influence on the color printing and register printing of the printing machine.
Another disadvantage of the mechanism is in that after the setting for register printing is achieved, the mechanism is not secured against axial shifting.
Another known device is provided with a shiftable bushing which is connected with a toothed ring mounted on the bearing of the forme cylinder. The toothed ring is in engagement with a worm gear whereby the shiftable bushing seats and is pressed by means of pressure springs on a carrier disk passing over an axial bearing on a helical drive gear which is shiftably arranged on the shaft of the forme cylinder.
A disadvantage of the described device is that it is controlled by means of a worm transmission from the front side of the machine or from another place where further clearance arises due to other transmission elements. The device forms a rigid unit, but the drive gear is controlled by elastic elements.
In another known device, a slidable bushing is arranged on a shaft of a forme cylinder. On the slidable bushing, a gear is mounted which is rigidly connected with a clearance up taking gear which is shiftably engaged with its teeth with the inner teeth of a toothed ring which is attached in a sleeve fixed on the forme cylinder.
A disadvantage of this device is that the taking up of clearance between the teeth of the gears can be carried out only before the mounting of the forme cylinder. Further taking up of the clearance of the teeth due to loosening of the forme cylinder is not possible.
A further disadvantage is that the device does not form a rigid unit so that during printing, the forme cylinder can shift.